Hydrostatic testing of pipe used in the oil and gas producing industry is generally accomplished by sealing a section of pipe at both ends and by injecting test fluid under pressure into the pipe through one of the seals. Cracks or irregularities in the pipe may be detected by observing leakage of the test fluid. The present invention hydrostatically tests the surfaces of pipe that abut each other in a pipe joint in order to determine the seal integrity of said surfaces against leakage.
Typically, each section of pipe possesses a threaded male end and a threaded female end so that the sections of pipe may be threaded together to make a string of pipe. The cylindrically symmetrical extreme end of the female end of each pipe is designed to firmly seat against the cylindrically symmetrical shoulder at the base of the threaded portion of each male end of each pipe. When the pipes are threaded together, the threaded portions of each pipe are not visible to anyone observing either the interior or the exterior surface of the pipe joint because the threadably engaged portions of each section of pipe are contained within the pipe wall.
The surface of the shoulder of the male end of a first pipe and the surface of the extreme end of the female end of a second pipe each comprise a sealing face surface on the respective ends of each pipe. These two sealing face surfaces meet at the point of juncture between the external surface of the male end of said first pipe and the external surface of the female end of said second pipe when a pipe joint is made up. When the sealing face surfaces of the adjoining male and female ends of said first and second pipes firmly abut each other, they prevent the escape of fluid from the interior of the pipe joint. That is, if fluid in the pipe leaks through the threaded portion of the pipe joint to the juncture of the sealing face surfaces in the pipe joint, then the fluid cannot flow through the juncture if the sealing face surfaces of the pipes forming the pipe joint are flat, smooth and undamaged.
Although various hydrostatic testing devices exist to detect leakage of test fluid past the threaded connection of a male end and a female end of threaded pipe, these devices detect leakage from the pipe joint as a whole. That is, such devices do not permit one to test the seal integrity of the sealing face surfaces separate and apart from testing the seal integrity of the engaged threaded portions of the male and female ends of threaded pipe.